4 - Lecture Notes PPT - PSY 440 - Placebo & Neurons & NTs

PSY 440 Psychopharmacology Ryan A. McKelley, Ph.D. LP, HSP UWL Department of Psychology Class 4: Placebo; How Neurons Work ● ● ● Ask Me Anything Housekeeping Lecture ○ Activity: Personal Placebos ○ Placebo and nocebo ○ How neurons work Words to live by “Don't ask yourself what the world needs; ask yourself what makes you come alive, and then go and do that. Because what the world needs is people who have come alive.” - Harold Whitman “There is a part of me that wants to write, a part that wants to theorize, and part that wants to sculpt, a part that wants to teach . . . To force myself into a single role, to decide to be just one thing in life, would kill off large parts of me. My career will form behind me. All I can do is let this day come to me in peace. All I can do is take the step before me now, and not fear repeating an effort or making a new one.” - Hugh Prather Housekeeping ● Debrief Mario’s visit ○ What were the highlights? ○ Any burning questions lingering? Placebos & Nocebos Estimated to be 30-85% of variance in tx effectiveness The Healing Art of Deception • • • • • Italian campaign of WWI (19431945) 60k Allied dead; 320k casualties Shortage of medicine Hero of story? Nursing assistant of anesthesiologist She injected soldiers with saline and said it was potent pain reliever • Inert injection ↓ agony which ↓ BP which prevented lifethreatening shock Placebo • • • Latin = “I will please” Originally referred to pleasant AND harmful effects of treatment 45% of prescribers admit to using them Nocebo • • • Latin = “I will harm” Termed emerged in 1980s Negative side effects of an inert treatment Pure vs. Impure Placebos • Pure • • • “sugar pills” Saline injections Impure • • • • Off-label use of meds; antibiotics for virus Lab test/physical exams Inactive medical devices Sham surgeries Placebo Response Factors • Pill color • • • Pill size • • • Red = stimulants/pain relief Blue = depressants/sleep aids Bigger pillsàbetter effect Bigger priceàbetter effect Type of treatment • Surgery > injection > capsules > tablets Active Placebo • • Placebo may account for 75% of anti-DEP effectiveness Active placebos may account for remaining 25% • Perceptible side effects that do not contribute to clinical effectiveness (Kirsch, 2010) Understanding Receptors Where Drugs Work Neurons & Neurotransmitters One Piece of Brain the Size of a Grain of Sand 100,000 neurons 2,000,000 axons 1 Billion synapses In the Entire Brain… 100 Billion neurons Each connected to 1,000 synapses = 1 Trillion synaptic connections In the Brain Each Second… 1 Trillion connections with an average of 1000 signals cross each synapse = Ten Quadrillion operations per second In the Brain Each Second Each of those 10 Quadrillion signals modulated by 1500 proteins and 1+ neurotransmitters Two More Brain Facts 1. No two neurons are separated by more than six steps. 2. Each neuron is services by 10 glial cells. Neuron Organization • • DendriteàNucleus (Cell Body)àAxon Memory trick = D-N-A What happens when NT is released? *See Sapolsky p. 690-691 1. 2. 3. 4. Increase amount of NT (“yell louder”) Increase amount of receptor on dendritic spine (“listen more acutely”) Decrease re-uptake pump (less NT removedà”amplify signal”) Decrease activity of degrading enzyme (less NT broken downà”amplify signal”) What happens after NT is released? • • • • Bind Re-Uptake via transporter Degrade Diffuse Neurotransmitters… …an oversimplification • • • • • • S - Serotonin (5-HT) – Mood, apathy, pain, panic, sleep, suicide D - Dopamine (DA) - Reward N - Norepinephrine (NE) – Motivation/Vigilance ACh - Acetylcholine (ACh) – Memory H - Histamine (H1) - Sedation GABA (inhibition) and Glutamate (excitation) – Cognition • FYI: Glutamate = Master switch of Brain, can turn on virtually all CNS neurons! Looking ahead… DUE by Tuesday • Read Lustig (2017) – Ch. 2 (Neuroanatomy)